Emotional dynamics and vascular change share a close and interactive relationship. The mechanisms underlying this important interaction, however, are not well understood. The purpose of this research project is to examine one aspect of this interaction: the physiological mechanisms underlying vascular changes produced in normal subjects by hypnotic suggestion. Highly hypnotizable college-age volunteers participate in experiments designed to examine cutaneous vascular responsivity: a) during baseline and task conditions, b) following hypnotic suggestion for bidirectional skin temperature change, and c) while in the normal and hypnotic condition. Blood flow and volume, muscle tension, respiration, heart rate, blood pressure and skin conductance are measured, and their interaction with temperature changes examined. Generalization of self-regulation to the normal waking state, as well as the regional specificity of the induced physiological changes, will also be evaluated. These investigations will provide: a) basic information about the interaction and normal ranges of blood flow and volumetric responses under resting and controlled stimulus conditions, b) new information about the anatomical site and physiological mode of action of self-regulation of skin temperature, and c) important baseline information for examination of migraine headache, Raynaud's disease and essential hypertension, all dysfunctional aspects of the relationship under investigation. Greater understanding of underlying vascular mechanisms may result in improvement of existing treatment and development of new modes of therapy.